To experimentally test the usefulness of SLFN11 as a marker of response to the dCRT regimen, we performed viability assays using previously established isogenic human cell lines differentially expressing SLFN11 (human leukemia CCRF-CEM SLFN11-proficient [parent] and -deficient [SLFN11-KO], and K562 SLFN11-deficient [K562 + vector] and -proficient [K562 + SLFN11] cell lines) [18] (Figure S1). Here, SLFN11 is linked to leukemia.